HTML and CSS Reference
Opera ( www.opera.com ) is an Internet suite that, in addition to web browsing, handles e-mail,
online chat, and more. Developed by Opera Software, it is a commercial project available free
of charge, and runs on many operating systems, including Windows, Linux, Mac OS X, Solaris,
and FreeBSD. It is also a very popular browser for mobile devices, such as cell phones, PDAs,
and game consoles. In development since 1994, Opera is a relatively old browser, and the ver-
sion number shows it. The most recent version of Opera at the time of this writing is version 9.
Opera is a small player when it comes to market share—the latest stats indicate the
browser is in use by less than 1 percent of all web surfers. However, it is notable in that support
for web standards, including CSS, has long been a priority at Opera. Although earlier versions
of Opera do have minor quirks in the way they render some web pages, it's safe to say the most
recent versions have very good support for (X)HTML and CSS, and are unlikely to cause you
any major headaches as you build CSS-based sites.
Microsoft's Internet Explorer ( www.microsoft.com/windows/ie/ ) is the most widely used web
browser in the world, no doubt in large part due to the fact that it is the default browser for
Windows, the most popular operating system in the world. The current version of IE is version 6,
which was released in the summer of 2001. Version 7 should be available by the time you
read this (although if Microsoft's history with shipping products on time is an indication, we
probably shouldn't count on that).
Although Microsoft created versions of Internet Explorer for several platforms, including
Windows, Mac OS X, Classic Mac OS, and Solaris, only the Windows version remains in active
After having won the browser wars of the late 1990s, Internet Explorer's market share was
up to around 96 percent in 2002. Since the releases of Firefox and Safari, it has steadily declined,
but it remains the dominant browser by a large margin. At the time of this writing, IE accounts
for about 85 percent of web traffic.
And yet, most standards-aware web designers and developers have a strong distaste for
Internet Explorer. While Microsoft has been criticized for several problems in IE, notably secu-
rity issues, the one that irks people building web pages is frustrating gaps in support for modern
web standards, especially CSS. Internet Explorer 6 was actually quite advanced in terms of CSS
support when it was released, but no significant enhancements have been made since 2001,
and other browsers have steadily gotten better and better. Web designers and developers are
frustrated at the time they spend working around IE's bugs, missing support, and proprietary
feature set when simple, clean, standards-based code should work across the board. Thankfully,
the release of Internet Explorer 7 should solve the vast majority of these issues, as Microsoft
seems to be placing a major focus on providing strong support for standards. However, it will
be a good while before most users have migrated from version 6 to 7, so we will certainly need
to deal with the frustrations of IE 6 for some time to come.
In this section, we'll detail some notable CSS support issues in IE 6. We'll show you how to
address these issues using a combination of sensible planning, workarounds, and hacks. (See
Chapter 6 for more on hacks and workarounds.)